Problem: Emily has biked her bike for a total of $18$ kilometers since she started biking daily. She has been biking $2$ kilometers each day. For how many days has Emily been biking?
Explanation: The number of days that Emily has been biking is the total number of kilometers biked divided by the number of kilometers biked each day. $18\text{ kilometers} \div 2\text{ kilometers per day} = \text{number of days biking}$ $18\text{ kilometers} \div 2\text{ kilometers per day} = 9\text{ days}$